The major objectives of this proposed project are: (1) to determine if putrescine and polyamine changes occur in the rat placenta due to altered growth rates; (2) to develop a radioimmunoassay for putrescine and the polyamines for early detection of altered growth by monitoring the urine, serum, and amniotic fluid of individual pregnant rats and (3) to determine if diamine oxidase plays a growth regulating role in the placenta by interacting significantly with putrescine and polyamine metabolism. These objectives will be met by: (1) experimentally inducing placental hypertrophy or degeneration in vivo by using the techniques of maternal endocrinectomy, steroid injections and fetectomy; (2) using newly discovered inhibitors of diamine oxidase and polyamine pathway enzymes in in vitro placental tissue incubations; and (3) correlating enzyme activites in vivo and in vitro with changing concentrations of pathway products, including the formation of gamma-aminobutyric acid from putrescine. It is hoped that these studies will develop biochemical tools that will allow the early detection of altered tissue growth patterns before deleterious functional changes occur, particularly in the placenta but more generally in any tissue, especially those subject to carcinoma.